The 67-year-old American television personality, who was pictured out in Malibu on Thursday, appeared on the talk show host's popular show in 2015 after transitioning.
She admitted to Ellen that she had been hesitant to accept gay marriage in the past, prompting the blonde star to describe her guest's views as 'confusing' in a later interview with radio presenter Howard Stern.
In her memoir, The Secrets of My Life, which has been obtained by Radar Online, Caitlyn says Ellen, 59, asked in a 'friendly voice' to discuss how her views on marriage equality has 'progressed over the years.'
Caitlyn wrote: 'I believed, as anyone would, that that was exactly what she wanted to talk about my progression in terms of changing attitude over the years.
'I am for it. I did not initially understand why marriage was so important, influenced no doubt by my own personal experience. Now I do, and it's a wonderful thing to see.'
'This discussion further alienated me from members of the LGBTQ community. Ellen's appearance on The Howard Stern Show, where in my mind she even more emphatically took what I said out of context, made it go viral.'
'I'm a traditionalist': Caitlyn Jenner on gay marriage & dating
The I Am Cait star - who has six children and has been married three times in the past - had admitted during her interview with Ellen that she was a 'traditionalist' who never used to approve of same-sex marriage, but her attitude had changed in recent years.
She said: 'I have to admit that I remember 15 years ago, 20 years ago, whenever it was that the whole gay marriage issue came up, I was not for it.
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'I am a traditionalist. I mean, I'm older than most people in the audience. I like tradition and it's always been between a man and a woman and I'm thinking I don't' quite get it.